Wireless telecommunications systems provide a convenient way for users to communicate. Typically, wireless telecommunications systems are made up of a series of mobile switching centers connected to base stations and landline telecommunications networks. The mobile switching centers are typically capable of controlling the operation of the base stations. In this regard, the base stations typically have the capacity to communicate with each other via base station controllers and to establish a fixed number of radio frequency (RF) traffic channels with remote mobile stations. The RF communications channels act as a conduit by which the mobile stations may ultimately communicate, such as with each other and/or landline phones, for example. Thus, as long as a mobile user remains within the geographic coverage area of the wireless system, communication with other mobile and landline users is possible.
To standardize the operation of wireless systems, several communication implementations have been developed. One such implementation, currently used in numerous wireless communication system deployments, is known as Time Division Multiple Access (TDMA). This communication technique is described under the TIA/EIA/IS-136 standard (IS-136). Accordingly, the IS-136 standard is incorporated by reference in its entirety so as to provide the reader with adequate background information regarding mobile station operation in an IS-136 telecommunications environment.
Current wireless systems allow landline users to place and receive calls with mobile station users. Additionally, mobile station users can place and receive calls with other mobile station users. Fixed mobile switching centers and base stations facilitate these calls by routing the calls between users and handling necessary overhead activities required to establish the RF traffic channels used to conduct the calls.
Typically, when a landline user or other mobile station user calls a mobile station user, the mobile switching center acts as an intermediary by alerting the mobile station of the attempted call via at least one RF traffic channel. After alerting the mobile station, the mobile switching center waits for a fixed time period, which defines a ringing cycle, to receive a response from the mobile station. A response indicates the mobile station is ready to accept the call. However, if the mobile station does not respond within the ringing cycle time period, the mobile switching center releases the call by terminating a call alert to the mobile station and signaling to the caller that the mobile station is unavailable, or alternatively redirecting the call to a message center to record a message for the mobile station user. During the ringing cycle, the mobile station produces an audible ringing or mechanical vibration to alert the mobile station user of the incoming call. If the mobile station user decides to answer the incoming call, a response is sent from the mobile station to the mobile switching center indicating that the call is to be accepted. The mobile switching center then sets up a connection on the existing RF traffic channel or establishes a second RF traffic channel where the call will ultimately be connected.
One of the major benefits to users of mobile phones is the ability to place or receive calls without being restricted to a fixed location as when using a landline phone. So long as the mobile phone maintains an RF communication channel with at least one base station, communication services are generally available. This allows mobile users to send and receive calls when away from their home or office and even while traveling in automobiles. However, having accessibility to instant communications may at times have undesirable consequences. In particular, unless the mobile phone is powered off, there may be no action a user may take to prevent the phone from proceeding through the entire ringing cycle, even in instances in which the user of the mobile phone desires to receive only non-real time, voice messages. This means that for every unanswered incoming call, the phone will ring for the entire ringing cycle until the call is released by the base station, sent to a voice message application on the mobile phone, or forwarded to a message center, each of which may be capable of receiving a voice message. Even if the user is able to mute the audible ringing, the call is still processed by the phone until released, sent to a voice message application, or forwarded to a message center. By requiring the mobile phone to process each call, the phone may occupy a traffic channel for an undesirable period of time, thus reducing system capacity during those periods in which calls are processed but ultimately not answered.